The Impact of Clinical Pathways on Adoption of Hypofractionated External Beam Radiation in Patients with Low- or Intermediate-Risk Prostate Cancer

Abstract

Hypofractionated external beam radiation (HF-EBRT) in low- and intermediate-risk prostate cancer provides non-inferior disease control with a more convenient regimen compared to conventionally fractionated external beam radiation (CF-EBRT). Two phase III trials, RTOG 0415 and CHHiP, were published in 2016 confirming the non-inferiority of HF-EBRT to CF-EBRT. However, HF-EBRT remains underutilized nationally. Clinical pathways (CP) are a method for standardizing care in alignment with evidence to avoid unnecessary variations in practice. We evaluated whether a change in our CP would increase utilization of HF-EBRT in patients with low- or intermediate-risk prostate cancer. We implemented a CP for management of patients with low- and intermediate-risk prostate cancer, which was modified in January 2018 to reflect HF-EBRT as the first-choice modality for patients planned for definitive EBRT without brachytherapy. We performed a retrospective analysis on 946 patients seen in consultation at one of 16 network radiation oncology sites between 2015 and 2018. All patients had low-risk (LR), favorable intermediate-risk (FIR), or unfavorable intermediate-risk (UIR) prostate cancer. Patterns of practice in patients with LR, FIR, and UIR prostate cancer were analyzed on a year-by-year basis. In patients treated with EBRT alone, the Chi-square test was used to determine whether utilization of HF-EBRT increased after CP modification. Based on treating physicians’ pathway selection at the time of consultation, from 2015 to 2018, utilization of HF-EBRT increased on a year-by-year basis in LR, FIR, and UIR subgroups (Table 1). Use of CF-EBRT decreased over time in all subgroups from 2015 to 2018 (LR, from 41.1% to 20.0%; FIR, from 55.6% to 35.7%; UIR, from 52.3% to 35.5%). Utilization of brachytherapy alone decreased during the same time period in LR patients (58.9% to 40.0%) but remained relatively stable in FIR (34.3% to 35.7%) and UIR patients (5.3% to 3.2%). Utilization of EBRT with brachytherapy boost remained stable among UIR patients (42.4% to 41.9%). Among patients treated with definitive EBRT alone, utilization of HF-EBRT increased after CP modification from 4.4% to 92.8% (p<0.001). Modification of our CP to reflect HF-EBRT as the first-choice modality for low- or intermediate-risk patients treated with EBRT alone increased the utilization of HF-EBRT from <10% to >90% over a short period of time. Despite the publication of phase III data indicating the non-inferiority of HF-EBRT in 2016, this change in practice pattern was not observed until we modified the CP in January 2018. Clinical pathways are an effective way to standardize practice patterns in alignment with the newest evidence.Abstract 2688; Table 1Risk Category2015201620172018Low Risk0%1.4%5.2%40.0%Favorable-Intermediate Risk0%0%3.7%28.6%Unfavorable-Intermediate Risk0%0%4.7%19.4% Open table in a new tab